Outside of the UK, bilingualism (or even trilingualism+) is the norm in EuropeĀ and, in some countries and/or regions, even expected. With that said, The Economist takes a look at the effect bilingualism has on a child’s brain.
Monitoring languages and keeping them separate is part of the brain’s executive function, so these findings suggest that even before a child can speak, a bilingual environment may speed up that function’s development. Before rushing your offspring into Tongan for Toddlers, though, there are a few caveats. For one thing, these precocious cognitive benefits have been demonstrated so far only in “crib” bilingualsāthose living in households where two languages are spoken routinely. The researchers speculate that it might be the fact of having to learn two languages in the same setting that requires greater use of executive function. So whether those benefits accrue to children who learn one language at home, and one at school, remains unclear.
It’s worth noting that the executive function is only a theoretical system, supposedly responsible for “planning, cognitive flexibility, abstract thinking, rule acquisition, initiating appropriate actions and inhibiting inappropriate actions, and selecting relevant sensory information”.